There are known in the prior art boxes or containers which are especially adapted to receive articles of cargo for shipment by aircraft.
Examples of containers of this type are shown, for example, in Luisada and Frieder Pat. No. 3,563,403 for a Cargo Box, Luisada Pat. No. 3,575,312 for a Refrigerated Cargo Box, Luisada Pat. No. 3,655,087 for a Lightweight Knockdown Container, and in our co-pending Application Ser. No. 286,462, filed Sept. 5, 1972, for a Smooth Operating Cargo Box, now U.S. Pat. No. 3,853,238. While boxes of this type may be provided with locks or the like in an effort to prevent unauthorized entry into the box, the possibility exists that a dishonest person may attempt to enter the box either by breaking the lock or by entering the box through one of the panels thereof. We have invented an alarm system for a cargo box for signalling an attempt by an unauthorized person to enter the box. Our system greatly adds to the security of the contents of the box. It is relatively simple in construction and operation for the result achieved thereby. It signals not only in response to a forced entry into the box by separating the panels but also a forced entry by cutting through one of the panels making up the box.